1. Field of the Invention
This invention relates to lubricant compositions, and, in one of its aspects, relates more particularly to lubricant compositions which are thermally and oxidatively stable and exhibit reduced tendency to deterioration. Still more particularly, in this aspect, the invention relates to such lubricant compositions as lubricant oils and greases, and also to other forms of organic media, in which these lubricants can be employed as blending stocks to modify their properties, for example such organic media as automatic transmission fluids, hydraulic fluids, heat-exchange fluids, and the like, in which the aforementioned stability against thermal and oxidative deterioration is an important requisite.
2.Description of the Prior Art
The importance of maintaining thermal and oxidative stability in lubricant compositions, for example in such representative areas as hydrocarbon lubricant oils and greases, or in any of the other aforementioned areas, is well known. Prior to the present invention, various lubricants or lubricant additives have been suggested for such purposee but have not been found to provide the desired degree of improvement. In some aspects either, or both, oxidative stability and thermal stability have not been significantly improved in the aforementioned compositions. In other instances, lubricants or lubricant additives employed for such purpose have proved to be costly, far outweighing the degree of improvement obtained.